structure of rna and dna 2.1

What is the structure of a nucleotide?

a pentose sugar
-a phosphate group (circle)
-a nitrogen containing organic base (rectangle) these are c,t,u,a,g

what is c

cytosine:

what is a?

adenine

what is t?

thymine

what is u?

uracil

what is g?

guanine

How is the pentose sugar, phosphate group and organic base joined?

in condensation reactions to form a single nucleotide (mononucleotide)

What happens when 2 mononucleotides join in condensation reaction ?

The bond formed between the deoxyribose sugar of one mononucleotide and the phosphate of another is called a phosphodiester bond. =and called a dinucleotide.

The structure of ribonucleic acid? 4)

-It is a polymer made up of nucleotides.

-a short polynucleotide chain in which the pentose sugar is always ribose and the organic bases are a,g,c,u.

-One type of RNA transfers genetic information from DNA to ribosomes
-other type involved in protein synthesis

who worked out the DNA structure?

Jams Watson and Frances crick worked out the structure of DNA, following the pioneering work of Rosalind franklin

What is the DNA structure?

-The pentose sugar is deoxyribose
-organic bases are =A,T,G,C

-DNA is made up of 2 strands of nucleotides
each of the strand is very long and joined together by hydrogen bonds formed between certain bases.

-The 2 polynucleotide strands in DNA twist around each other to form a double helix. They form the structural backbone of DNA molecule

What is base pairing ?

The bases on the 2 strands of DNA attach to each other by hydrogen bonds.it is these hydrogen bonds that hold the 2 strands together

a+t
c+g

they are said to be complementary to each other

the quantities of a+t is the same
the quantities of c+g is the same

why is DNA a stable molecule?

-the phosphodiester backbone protects the more chemically reactive organic bases inside the double helix.

-hydrogen bonds link the organic base pairs, forming bridges between the phosphodiester uprights
3 hydrogen bonds between c+g
the higher the proportion of c-g parings, the more stable it is

what is the function of dna?

-carry gentic infromation and pass it

list the ways in which the DNA molecule is adapted to carry out its function

-it has a very stable structure .most mutations are repaired.

-its 2 separate strands are joined only with hydrogen bonds, which allow them to separate during DNA replication and protein synthesis

-large so carriers lots of genetic information

-base pairing leads to DNA being able to replicate and to transfer information as mRNA

What is the function of rna?

It acts as a messenger molecule ,it helps transfer information from dna to proteins .

It also regulates protein synthesis

The differences in the structure of nucleotide in DNA and RNA?
6)

in DNA, the pentose sugar is called deoxyribose
in RNA, it's called ribose.

-chain length
DNA long
RNA short

-strand number
DNA=double
RNA=single

-organic bases
DNA=ATCG
RNA=AUCG

chemical stability
DNA=very strong h bonding
RNA=less stable

Function
DNA+carries genetic information
RNA+transfer genetic information+involved in protein synthesis.

what are ribosomes made up of?

• ribsomes are formed from RNA and proteins